Nirmal power systems offers line interactive ups systems. These have built in avr to take care of 150 v to 280 v ac line fluctuation, and built in smf battery to give 20 minutes back up with one computer in 500 va model and 60 minutes back up in 600 va model.
Other features: built in rfi/emi filter and spike suppressor; built in regulated battery charger; pwm mosfet technology inverter for highest effi ciency; rapid transfer from mains to inverter mode for best computer grade un interrupted power; restart delay facility to protect computer from sags and surges; advance alarm led and buzzer for no hassle shut down of pc; no load cut off facility to prevent un wanted discharge of battery; over load protection automatic shutdown; and cold start to allow the usage of computer on battery power even when there is no mains available to start with.
